Compressed folder.. files added not compressed

I don't know if a Windows update caused this (if so, it was several months ago), but I notice that when I add, say a bmp file to a folder which is set to compress contents, that new file does not become compressed itself. I have to compress any such file individually. Even unchecking, closing, and resetting the Properties/advanced compress option for the folder does not work.

I am sure that once upon a time, when I set a folder to be compressed, any file I added to it would automatically be compressed. Any idea why that is no longer so?

Thanks.

I use WinRar and it works flawlessly.
You can create a new compressed archive and add, remove files, you can even set a password for each file or sub folders among many other features.

Yes, I have that, thanks, though I tend to use 7z mostly. I was meaning the default Windows 7 compression, when you set a folder to compress its contents via the properties box, rather than external zip programmes.

I know what you mean and that is why I use WinRar (or equivalent) so I save time.
I had a similar problem in the past and I know that Windows has too many unpredictable issues due to who knows.
Lets see is someone has the right solution.

I found this on another webpage which doesn't answer your question but just verifies what you're finding-

File Compression Behavior
If you move a file from a DIFFERENT NTFS drive into a compressed folder, it is also compressed.
If you move a file from the SAME NTFS drive into a compressed folder, the file retains its original state, either compressed or uncompressed.